Flush receptacle and plug.



lt'e, $94,703. PATENTED JULY 28,1908. 1?. W. sANmmJ; FLUSH REGBPTAGLE AND PLUG.

APPLICATION FILED SEPT.12, 1.905.

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M'finesses FRANK w. SANFORD,

rriusn ascsrracnnann PLUG.

To all whom it may concern."

Be it knownv that L'FRANK W. SANFORD, a citizen of the United States, residing at Schenectady, county of Schenectady, and State of New Y ork, have invented certain new and use ful Improvements in Flush. R eceptacles and Plugs, of which the following is a specification.

This invention relates to connectors for a electric circuits, of the type in which a receptacle containing main-line terminal contacts islet in flush with a wall or floor, while the terminal contacts'of the branch line are car ried on a plug,'adapted to be thrust into the receptacle in such a position as to bring the two sets of contacts together and connect the branch line with the main line.

'Heretofore, when the plug was withdrawn the mouth of the receptacle has been closed by one or more covers or shutters, either hinged or arranged to slide laterally. In

either case they re uired to be opened by hand before the pug could be inserted. Moreover, there was no way to lock the shutter so as to prevent its being. openedand the circuit. contacts exposed and meddled with 'or injured.

The object of my invention is to provide a flush receptacle with a shutter which will be opened automatically when the plug is pressed against it, but which will be locked against unauthorized tampering when the plug is withdrawn,

To this end the invention consistsin awall receptacle having stationary line terminals, a yielding shutter provided with locking devices, and'a plug carrying branchline terminals and means for unlocking the shutter, so that said shutter can be unlocked and forced inward when the plug is pressed against it. The specific construction is hereinafter set forth, and is particularly pointed out in the claims.

In the accompanying drawing, Figure 1 is a frontelevation of my improved wall receptacle, partly in section; Fig.2 is a longitudinal section of the same;v Fig. 3 is a front elevation with the face-plate and shutter removed; Fig. 4 is an end view of the plug, partly in section; Fig. 5 is a side view of the plug; Fig. 6 is an edge view of the front view of a modified shutter and lock; Fig. 8 is a section of the same; and Fig. 9 is a detail.

The receptacle has ametal face-plate 1 containing an oblong opening which is closed Specification of Letters Patent.

The face-plate is secured to a casing 2 of insulatmg material, such as porcelain, by means of screws 3 which enter tapped holes in small plates of'metal 4 fastened to. the casingby screws '5 and preferably having offset-portionsfi letinto shallowr'ecesses in the back of the faceplate, to assist in retaining said plate in place. 1

The casing has an oblong cavity registering with the opening in the face-plate, and adapted to receive a plug of similar crosssectlon. At each side of the cavity are lat eral recesses in each of which is located a lineterminal contact, consisting preferably of a strip 7 of resilient metal bent into Li -shape,

onsron OF SOHENEO'IADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW, YORF i PatentedJuly 28, 1908. Application filed. September 12, 1905. sem tsaa'laisv.

T by the yielding shutter hereinafter described. I

with one leg secured to a metal plate 8 carrying a binding-screw 9. A hole 10 is formed through. the casing adjacent to said plate to enable one of the line-conductors 11 to be led in and connected by the binding-screw with the contact 7. The plug is made ofv insulating material, and has a head 12 and a body 13, the latter being oblong in cross-section.

and of a size suitable to pass through the hole in the face-plate and enter the cavity the casing. Each edge of the plug has a recess in which is held. an L-shaped piece of metal 14 constituting one of the branch-line terminal contacts, the branch lines being led through a passage in said plug and clamped to the contacts 14 by binding-screws l5. l/Vhen the plug is thrust. into the casing and given a quarter turn, the portions 14 of the contacts are carried under the free ends of the contacts 7, thereby placing the branch line in circuit with the main line and also looking the plug in the receptacle.

l Vhen the lug is withdrawn, the opening in the face-p ate is automatically closed by a shutter, which is provided with looking de vices, preferably spring-actuated. The shutter consists preferably of a shallow box composed of a top-plate 16, a bottom-plate 17, and side-pieces; or spacing-strips 18, all r1veted' together, with openings in the ends. The spring catches which lock the shutter are preferably mounted therein. Those illustrated in Fig. 1 of the drawings consist of flat bolts 19 slidably arranged between the plates 16, 17, with their noses projecting through the holes in the ends of the shutter. The shanks of the bolts pass by each other and have L-shaped ends forming laterally-projecting lugs which overlap and are preferably oblong opening,

.yieldingly supported, as before,

to t e bottomplate 17 concentric with the hole 20. In the lace-plate, at the ends of the are formed recessesQZ to receive the noses of the bolts, which are urged outwardly bysprings 23. By thrusting a wed e-shaped or tapering implement into the hole 20, the L-shaped ends of the bolts will be forced apart and their noses with drawn from the recesses,

thereby unlocking the shutter. g I

In order to unlock the shutter automatically when the plug is inserted into the recep tacle, said plug is provided with a tapered pin 24 projecting from its end and adapted to enter the hole 20 when the lug registers with the opening in the face-p ate.

The shutter is yieldingly supported on helical springs 25 seated in sockets'26 in the casing and encircling guide-pins 27 projecting inwardly from the shutter. In order to arrest the shutter with its top-plate flush with the face-plate, the ends of the bottom-plate 17 project slightly, as shown in Fig. 1, so as to engage the under-side of the tace-plate when the shutter'is urged outwardly by the springs, I

The operation is as follows: The plug is placed in line with the shutter and the pin 24 is pushed into the hole 20, thereby unlocking the shutter. By a continuous inward move ment, the plug can be thrust into the receptacle, pushing the shutter inward before it against the tension of the springs 25. When fully home, the lug can be rotated a quarter turn, to close t e circuit and lock the plug, the shoulders 28 thereon passing under the face-plate at the sides of the oblong opening.

In the modification shown in Figs. 7 and 8 of the drawing, the shutter 29 is a solid plate on the springs 25. The shutter is locked in its closed position by two spring catches 30 se cured at the ends of the cavity in the casing. These catches spring in under the ends of the shutter whenit has face-plate. To unlock said catches, the-shut- .ter carries on its under side two bell-crank levers 31, whose short arms bear against the catches while the long arms have studs 32 projecting up. through a hole in the shutter. *ach stud is preferably semi-cylindrical, as shown, so that the two together iill the cylindrical hole. On the plug is a cylindrical pin 33 having a blunt end adapted to engage with said studs and force them inwardly, thereby causing the levers to spread apart the two spring catches and release the shut ter. The plug can then be pushed into the receptacle and rotated to close the circuit. The shutter locks automatically whenthe plug Withdrawn.

become flush with the sear/es N hat I claim as new, and desire to secure by Letters Patent of the United States, is,'-

1. In a flush receptacle, the combination with the casing and the face plate, of a shutter yieldingly sup orted, and means for lock ing it in its close position.-

2. In a flush receptacle, the combination with the casing and the face-plate, of a shutter yieldingl supported, and spring-actuated catches for coking it in its closed position.

3. In a flush receptacle, the combination with the casing and the face-plate, of a shu tter yieldingly sup orted, and locking devices carried by said shutter for retaining it in its closed position.

I ,4. In a flush receptacle, the combination with the casing and the face-plate, of a shut ter' yieldingly supported, and sliding bolts mounted on said shutter for retaining it in r the combination its closed position.

5. In a flush receptacle, with the casing and the facelate, of a'shutr ter yieldingly supported, sliding boltsfon said shutter having overlapping lugs, and springs, urging said bolts outwardly.

6. In a flush receptacle, the combination with thecasing and the face-plate, of a shutter yieldingly supported and comprising a top-plate and a bottom-plate, sliding bolts between said plates having overlapping lugs, and springs urging said bolts outwardly, said plates having holes in line with the nieet' ing faces of said lugs.

7. In a flush receptacle, the combination with the casing and the "face-plate, of an and face-plate, a yielding shutter, spring catches for said shutter, and a pin on said plug for actuating said catches to unlock them.

10. The combination wlth a plug, of a flush receptacle therefor comprising a casing and face-plate, a shutter yieldingly s'up ported, sliding bolts on-said shutter having overlapping lugs, and a tapering pin on said plug adapted to enterv between said lugs.

In witness whereoi, I have hereunto set my hand this 11th day of September, 1.905.

FRANK W. SANFORD.

Witness es BENJAMIN 13. Picnic, IIELEE Unseen.

tacle, the combination 105 to the line of movement 110 

